Catheters, such as central venous catheters, are used for a variety of diagnostic and therapeutic purposes, including the administration of fluid and pharmaceutical agents, and for hemodialysis in patients with renal failure. Unfortunately, central venous catheters lumens are prone to occlusion due to thrombosis from retrograde blood flow. In some cases, the thrombosis can be cleared from the catheter. In other cases, the catheter must be removed and a new catheter placed. Each new catheter placement is associated with a risk of complications, including infection, hemorrhage, pneumothorax and embolus.
Some central venous catheters have a unidirectional valve at the distal catheter tip to prevent retrograde blood flow. However, catheters with such valves still occlude due to thrombosis from retrograde blood flow and the valves tend to disadvantageously impede antegrade fluid flow.
Therefore, it would be useful to have a catheter that was less prone to thrombosis from retrograde blood flow. Additionally, it would be useful to have a method of delivering fluid and pharmaceutical agents, or for performing hemodialysis, that is associated where a lower incidence of catheter replacement due to thrombosis of the catheter from retrograde blood flow.
According to one embodiment of the present invention, there is provided a catheter for the administration of fluid or pharmaceutical agents, or for hemodialysis. The catheter comprises a proximal control end comprising a housing with a proximal end and a distal end; a distal delivery end; an elongated intermediate portion between the proximal control end and a distal delivery end; one or more than one delivery lumen within the intermediate portion extending from the proximal control end to the distal delivery end; one or more than one inflation balloon in each delivery lumen; and one or more than one inflation lumen in the intermediate portion extending from the proximal control end to the one or more than one inflation balloon in the one or more than one delivery lumen, and connected to the one or more than one inflation balloon through one or more than one fenestration. The proximal control end further comprises a mechanism for aspiration and injection of fluids through the distal delivery end, and the proximal control end further comprises a mechanism for controlling inflation of the one or more than one inflation balloon.
In a preferred embodiment, the one or more than one delivery lumen is two delivery lumens. In another preferred embodiment, the intermediate portion comprises an external surface and the one or more than one delivery lumen comprises an intraluminal surface, and the external surface or the intraluminal surface or both comprise at least one hydrophilic coating or comprise heparin molecules bound to the external surface or to the intraluminal surface, or both, to reduce the accumulation of thrombus and fibrin on these surfaces. In another preferred embodiment, the housing comprises one or more than one anchoring device.
In another preferred embodiment, the mechanism for aspiration and injection of fluids comprises one or more than one combined aspiration and injection port. In a particularly preferred embodiment, the combined aspiration and injection port is concave toward the distal end of the housing.
In another preferred embodiment, the one or more than one combined aspiration and injection port has a distal end and where the mechanism for aspiration and injection of fluids further comprises one or more than one aspiration and injection conduit connecting the distal end of each port to the one or more than one delivery lumen. In a particularly preferred embodiment, the mechanism for aspiration and injection of fluids further comprises constricting means for constricting the aspiration and injection conduit.
In another preferred embodiment, the mechanism for controlling inflation of the one or more than one inflation balloon comprises inflation means and deflation means. In a particularly preferred embodiment, the inflation means comprises a reservoir and an inflation actuator. The housing comprises a superior surface, and the inflation actuator can comprise a tactile recognizable surface that projects from the superior surface of the housing.
In one embodiment, the inflation means comprises an elastic bulb. In a preferred embodiment, the inflation means comprises a rigid upper unit slidably fitting into a rigid lower reservoir and separated by a reservoir spring coil within the reservoir.
In a preferred embodiment, the reservoir connects to the one or more than one inflation lumen through an antegrade flow conduit, and the inflation means further comprises a one-way, antegrade flow valve between the inflation lumen and the antegrade flow conduit. In another preferred embodiment, the reservoir connects to the one or more than one inflation lumen through one or more than one retrograde flow conduit, and where the inflation means further comprises a one-way, retrograde flow valve between the one or more than one inflation lumen and each retrograde flow conduit.
In another embodiment of the present invention, there is provided a diagnostic or therapeutic procedure in a human or animal. The method comprises the steps of providing a catheter according to the present invention, placing the catheter subcutaneously into the human or animal with the distal end inserted into a target vessel, injecting fluid into or aspirating fluid from the proximal control end of the catheter, and allowing the fluid to flow through the distal delivery end. The method can further comprise anchoring the catheter to subcutaneous tissues of the human or animal. The method can also comprise preventing flow through the distal delivery end by inflating the one or more than one inflation balloon in the distal delivery end. Inflating the one or more than one inflation balloon in the distal delivery end can be achieved by depressing a portion of the proximal control end through skin overlying the placed catheter.
The method can further comprise allowing flow through the distal delivery end to resume by deflating the one or more than one inflation balloon in the distal delivery end. Deflating the one or more than one inflation balloon in the distal delivery end is achieved by depressing a portion of the proximal control end through skin overlying the placed catheter.